A solar cell is an element for generating electric power from solar energy using various photoelectric effect materials.
Such a solar cell generally generates a photoelectromotive force using a P-N junction semiconductor cell, multiple solar cells are connected in series/parallel to configure a solar cell module having a specific capacity, these modules are connected to configure an array, and the array is installed in a power generation area.
FIG. 1 is a schematic diagram illustrating a general photovoltaic system.
The photovoltaic system includes: multiple solar modules 11a and 11b which produce DC current from solar energy; multiple junction boxes 12a and 12b, each of which is connected to one solar cell module; a combiner 13 which receives and combines the DC current outputted by the multiple solar cell modules 11a and 11b through the multiple junction boxes 12a and 12b; and an inverter 14 which converts the DC current generated by the combiner 13 to an AC power and provides the converted AC power to a load 15.
Such a photovoltaic system is further provided with equipment (ground relay, fuse switch, and the like) to operate the system in a safe way.
The junction boxes 12a, 12b are wired to provide the current generated by the solar cell modules 11a, 11b to the combiner 13, has a bypass element unit (bypass diodes) installed therein which allows electricity to bypass a certain solar cell module generating low power, or has a metallic heat sink to avoid overheating.
Meanwhile, in a conventional photovoltaic system, a monitoring part 16 for managing, controlling and monitoring the system is connected to an inverter 14 and therefore the process of the power produced by the multiple solar cell modules 11a, 11b, combined by the combiner 13 and then converted into a utility power by the inverter 14 may be managed, controlled and monitored.
However, the conventional photovoltaic system is not provided with any means for monitoring or controlling a fault or performance degradation of an individual solar cell module at all, and therefore the operating state of an individual solar cell module was unable to be monitored.
Further, even in the case where a fault of an individual solar cell module is sensed, it is unable to easily perform a fault management during the operation state when the multiple solar cell modules are continuously producing power, due to a risk of accident such as an electric shock or current leakage.
Furthermore, the photovoltaic system is typically installed outdoors, and thus involves a huge amount of expenses in the early installation stage. However, once the photovoltaic system is installed, it continuously produces electricity using solar energy to generate revenue.
This leads to a theft of the solar cell module for reuse since the conventional solar cell module may be compatibly reused with other photovoltaic systems, and such a theft of a solar cell module is a great obstacle to spreading the photovoltaic system.